Model railway car undercarriage



FIG. 1 is a top plan view of an ornamental design for a model railway car undercarriage, showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a right side elevation thereof;

FIG. 4 is a left side elevation thereof;

FIG. 5 is a front elevation thereof; and,

FIG. 6 is a rear elevation thereof. 

The ornamental design for a model railway car undercarriage, as shown and described. 